The invention relates to a method for recycling a waste wire harness constituted by electric wires each coated with a resin composition containing an olefin-based resin and magnesium hydroxide mixed as a fire retardant with the olefin-based resin.
Wire harness has been used popularly as an electric wiring system in a vehicle or another apparatus such as a household electrical appliance, a business machine or an information machine. Heretofore, electric wires each using a vinyl chloride resin as an electrical insulator or as a coating material such as a sheath became the mainstream of electric wires constituting the wire harness. However, the vinyl chloride resin generates a harmful hydrogen chloride gas which has a bad influence on human bodies and causes a corrosion of the apparatus when the vinyl chloride resin burns. Hence, a so-called non-halogen or low-halogen fire-retardant resin composition containing an olefin-based resin and magnesium hydroxide mixed as a fire retardant with the olefin-based resin has begun to be used popularly as an electrical insulator or a coating material such as a sheath of each electric wire in recent years. With the advance of popularization of the so-called non-halogen or low-halogen fire-retardant resin composition, a wire harness constituted by braided electric wires each using the so-called non-halogen or low-halogen fire-retardant resin composition as an electrical insulator or a coating material such as a sheath has begun to be used popularly.
On the other hand, as a method for recycling waste of a wire harness constituted by electric wires each using a vinyl chloride resin as a coating material (hereinafter also referred to as “vinyl chloride-coated wire harness”), JP-A-2002-313164 discloses a related-art method having the steps of: crushing the waste vinyl chloride-coated wire harness to obtain crushed particles; sorting the crushed particles into crushed iron particles, crushed copper and copper alloy particles and crushed resin particles; processing the crushed iron particles as scrap ion; reclaiming the crushed copper and copper alloy particles as copper; and landfilling and conserving the crushed resin particles as industrial waste. The crushed resin particles may be dechlorinated so that they can be used as a reducing agent in place of coke in an iron-making blast furnace.
There has been never proposed any efficient recycling method which is applied to a wire harness constituted by electric wires each using a non-halogen or low-halogen fire retardant resin composition as a coating material, that is, a wire harness foreseen well to become the mainstream in the future and by which magnesium hydroxide as a fire retardant can be collected and reused. Generally, 100 parts by weight of polyolefin-based resin contain about 50 to 200 parts by weight of magnesium hydroxide. If magnesium hydroxide can be collected and reused efficiently, the material cost of electric wires can be reduced greatly.
In addition, in the existing circumstances, waste members such as connectors and junction boxes accompanying the electric wires of the wire harness are generally processed by a method of crushing and landfilling the waste members. No effective method for recycling the waste members has ever been established.